Multiple hitch for offset disk harrows



March l0, 1953 L. E. HECKATHORN MULTIPLE HITCH FOR OFFSET DISK HARROWS Filed March 24, 1947 5 Sheets-Sheet l f/vvE/vrop: om E HEC/m mop/v 5y H15 ATTORNEYS March 10, 1953 L. E. HEcKATHoRN 2,630,662

MULTIPLE HITCH FOR OFFSET DISK HARRows Filed March 24, 1947 5 Sheets-Sheet 2 March l0, 1953 E. Hr-:cKATHoRN 2,630,652

MULTIPLE HITCH FOR OFFSET DISK HARROWS Filed March 24, 1947 I5 Sheets-Sheet 5 529:4 Ilnmllw'" @a a 5 www' g "f Patented Mar. 10, 1953 MULTIPLE HITCH FOR OFFSET DISK HARROWS Loyd E. Heckathorn, Santa Ana., Calif., assignor to Towner Manufacturing Co., Santa Ana,

Calif., a partnership Application March 24, 1947, Serial No. 736,848

21 Claims.

This invention relates to draft and control mechanisms for implements, and particularly to those mechanisms frequently known as hitches. The present mechanism is a hitch especially adapted to use with offset disc harrows having a plurality of relatively shiftable forward discing units in the form of gangs of earth cultivating discs, wherein such forward discing units are used in conjunction with a rearward gang, or gangs, of discs which operate normally in a position transverse of the line of forward draft of the apparatus as a whole and with respect to which the forward discing units are relatively shiftable to offset or angular positions. Such a series of forward discing units is here termed a squadron and the present hitch mechanism used in conjunction therewith will be referred to as a multiple hitch or a squadron hitch.

In disc harrows of this general type which have been used heretofore, positioning mechanisms adapted to assure proper operating relationship of the squadron units have included very heavy hitch mechanisms which at the same time served as squadron positioning devices, such heaviness being required for the purpose of properly positioning the units of the squadron in offset position during normal discing use. Such heavy hitch mechanisms have imposed a heavy dead weight forward of the units of the squadron which has resulted in undue burying during normal operation of the forward disc gangs in the earth, as compared with the penetration of the rearward disc gang, or gangs, into the earth lduring normal operation.

One of the principal objects of the present invention is to provide a squadron hitch which will overcome the objectionable feature of imposing undue dead weight upon the disc units of the squadron.

Another important object of the invention is to provide a hitch for squadron disc harrows having spacing and position-maintaining means for the disc units of the squadron that can be positioned rearward of the forward edges of the squadron units as a group rather than forward thereof. More generally stated, it is also an object of the invention to provide a squadron hitch whereby the incidental weight of positioning means for the units of the squadron is shifted from a position forward of the squadron units to a more rearward position, whereby not only to more nearly equalize the load, but also to reduce the dead weight load heretofore imposed by the mea-ns which positions and Astates the units of the squadron.

It is also an object of this invention to furnish in a squadron hitch spacing and Ipositioning means for the units of the squadron which is disposed above the plane of operation of the squadron units, whereby to eliminate any necessity for shaping the spreading or spacing means to provide for clearance of the forward or squadron discing units during shifting between. positions substantially transverse to the line of draft and offset positions angularly arranged with respect to the line of draft.

Another object is to provide in a squadron hitch spacing and spreading means which serve to position the discing units of the squadron whereby such means may be relatively small in size and light in weight, being at the same time positioned above the operating plane of the discing units, thereby to reduce the dead weight load of such spreading and positioning means to a very small value as compared to 'prior structures, and to a minimum lconsistent with the strength necessary for proper maintenance of the relative positions of the squadron units. An incidental object is to make it possible to establish an optimum weight value of such spreading and `positioning means, properly to locate such spreading and positioning means, and to dis-pose its weight at the most effective position on the narrow structure.

A still further object of this present invention is to furnish in a squadron type disc harrow spreading and spacing means for the units of the squadron which shall be of minimum weight and so disposed as to impose a minimum dead load upon the squadron units, while `being at the same time adapted to maintain during all. operating conditions a required parallelogram of forces whereby to insure proper offset 4or angularity of the forward or squadron units with respect to the rearward disc unit when in discing position, and to insure proper alignment of the forward and rearward units for turning, transport, and other non-discing operations.

Still another object is to provide a hitch means for squadron disc 4harrows wherein the draft means attached to the forward portions of the units of the squadron may be simplified to include only light weight draw ybars or tongue .members which may be pivotally mounted, pivotally connected together and adjustably yconstructed as required.

It is a further object of the present invention to provide a squadron type disc harrow having spreading and spacing means for the units of the squadron disposed above their yplane of operation and cooperating with means for limiting or controlling the amount of offset of the squadron units and for automatically releasing such offsetting Imeans or positively establishing the offsetting means as required for the purpose of operation of the entire harrow mechanism.

in general it is also an object of the invention to provide an improved and simpliiied hitch structure for squadron type disc harrows.

Further objects of this invention are to provide means for locking in adjusted position means which have been set to accomplish a given odset required for given discing operations, and also to provide means by which certain parts with which such locking means is associated may be moved or unlatched so that the offset discs may shift when turns in one direction are being made, the locking means itself being undisturbed whereby the initial offset is automatically restored when the turns are completed.

Other objects and various features of the invention will become apparent to those skilled in the art upon reference to the following specication and accompanying drawings wherein certain embodiments of the invention are disclosed for the purpose of illustration.

In the drawings:

Fig. l is a perspective View disclosing the invention as applied to a squadron type disc harrow wherein two forward or squadron units are employed, the forward units being shown in angularly disposed or offset discing relationship with respect to rearward gangs of discs;

Fig. 2 is a plan view of the disc narrow shown in Fig. l, the odset relationship of the forward units being indicated in broken lines, the forward units when in transport position, or other nondiscing position, being indicated in full lines;

3 is a vertical section as approximately indicated by the line 3 3 of Fig. 2;

Fig. l is an elevational fragmentary detail Vtaken approximately from the lines i-lfl of Figs.

2 and 3 and showing on an enlarged scale the structure of the spacing or spreading bar constituting the positioning means of the hitch, and also showing the manner of mounting such spreader bar;

Fig. 5 is a fragmentary horizontal detail taken approximately as indicated by the arrow 5 of Fig. 3, portions being broken away revealing parts in horizontal section, and showing a manually operable locking mechanism;

Fig. 6 is an elevational detail taken approximately from the line @-6 of Fig. 5;

Fig. 7 is a fragmentary vertical elevation, taken on the line i--l of Fig. 2 and showing the hinged means for connecting the two disc gangs or discing units constituting the rearward discing mechanism in the embodiment illustrated; and

Fig. 3 isa fragmentary showing as indicated by the arrow 8 of Fig. l, and on an enlarged scale, of automatic unlatching mechanism, seen also in Fig. 2, which permits automatic returning of the squadron disc units to a non-discing or transport position when a right hand turn is being undertaken.

As best illustrated in the perspective view of Fig. l, an important member of the construction of this invention is the overhead spacer or spreader bar it whose main length is disposed horizontally in a plane above two forward discing units generally indicated at i2 and I3 respectively. Each of the discing units I2 and I3 comprises a top frame having a front rail I6 and a rear rail l5, which rails are conveniently formed from angle iron, and members I6 connecting the rails It and I5 and providing mountings for axles I'I of gangs of dis-cs I8. Each of the units I2 and I3 is also provided with a cross strap 2B secured to and connecting the forward and rearward rails I4 and I5.

The ends of the spreader bar I0, which also acts as a tie bar between the units I2 and I3, are secured to the cross straps 2G through the medium of swivel mounts 2 I. As seen in Fig. 4, the swivel mount 2i includes ears 2Ia between which the depending ends Ia of the spreader bar Il) are secured as by means of bolts 22. The base of each swivel mount 2l is connected with the respective cross strap 2Q by means of a swivel pin 2li on whose lower end is secured an anchor nut Z5.

inasmuch as the parts of a disc harrow are commonly referred to as being at the right side or the left side of the harrow from the standpoint of direction of forward travel, the discing unit I2 will at times be referred to as the left discing unit, and the discing unit I3 will be referred to as the right discing unit, and the corresponding sides of the harrow will be referred to as the right and left sides respectively. Similarly, turning of the harrowV toward the side on which the discing unit I3 is located will be referred to as a right hand turn, and a turn in opposite direction will be referred to as a left hand turn.

According to the present squadron construction as illustrated, the left ends of the frames of the discing units I2 and I3 are pivotally connected, for movement in a horizontal plane, to corresponding portions of a rearward discing mechanism 2'1, which is composed of a left gang of discs 23 and a right gang of discs 29. These two disc gangs are carried in frames similar to those of the discing units I2 and I3, these frames including forward rails 30 and rearward rails 3i appropriately connected by end bars 32. Adjacent end bars 32 of the frames for the two gangs of discs 28 and 29 are shown (Fig. 7) as being hingedly connected by a hinge 33 comprising a hinge pin 34 mounted in appropriate brackets 35 secured to the respective end bars 32. By means of this horizontal hinge mounting, the two rearward gangs of discs are adapted to rise and fall in passing over rolling ground while their median lines are maintained in transverse alignment.

The pivotal mounting of the left ends of the discing units I2 and I3 to the forward rails Sil of the rearward discing mechanism is effected through the medium of vertical hinge pins 3B (Figs. 1, 2 and 3) which are positioned by means of brackets 39 projecting rearward from the rearward rails Irs of the discing units i12 and i3 and cooperating brackets 4i) projecting forward from the forward rails 3e of the framework for the rearward gangs of discs 28 and 2s. The brackets 39 and 40 are used in conjunction with cooperating braces 39a and dta appropriately connected with the brackets 39 and it and with the respective rails I5 and 30 of the mentioned disc frames. A spacer sleeve t2 disposed about each hinge pin 38, as seen in Fig. 3, is employed to maintain the desired relationships.

For the purposeV of pulling the narrow by means of a tractor or other appropriate draft devise, a tongue or draw bar structure is employed, which, as shown, is in the form of a rigid metal draft link and an adjustable rigid metal link @5. rl'he link 45 has a forward offset extension ld disposed substantially in line with the normal direction of travel of the barrow, the forward end of the extension a being provided with an eye 4'I for connection with a clevis pin or the like on the tractor or other draft mechanism. At the point of offset of the draft link 45, this link is provided with an appropriate double bracket 48 which receives a pivot bolt 4S serving to pivotally attach to the link 45 the adjacent end of one link member 50 of the link 46. The link member 50 is adjustably connected with a second link member 5I as by means of a series of bolts 52 adapted to be selectively received in corresponding holes in the two link members, as indicated in Figs. 1 and 2. The rearward end of each of the links 45 and 416 is provided with an appropriate eye member 53 which may be in the form of a U-shaped piece of rod welded to the opposite sides of the link. These eyes 53 are in turn received in appropriate eyes carried by clevises oi similarly appropriate attaching elements 54 which are in turn bolted or otherwise suitably secured to forward extensions 25a of the cross straps 2li mounted upon the rails i4 and I5 of the discing units I2 and I3. This construction of draw bar is relatively light in weight, and yet sufficiently strong and rigid for all required purposes. It imposes but slight dead weight upon the tractor or other vehicle and upon the two squadron discing units I2 and I3. Even in conjunction with overhead positioning of the spreader bar I, the

overall amount of dead weight carried by the discs I8 of the two units I2 and I3 is comparatively small and constitutes a non-objectionable practical minimum.

Upon forward draft of the harrow by the draw bar mechanism composed of the draft links 45 and 46, the two discing units I2 and I3 are caused to swing about the pivots provided by the vertical hinge pins 3B from the non-discing position of Fig. 2 toward the offset or angular discing position illustrated invFig. 1. Unless the forward swinging movement in a horizontal plane were limited, the movement would continue until the pivot point defined by the pivot bolt 4S of the draw bar mechanism, the mounts 2| and the respective hinge pins 38 assumed as nearly straight line positions as possible, considering the spacing and positioning action of the spreader bar I. To accomplish the necessary limitation of forward swinging movement, the two discing units I2 and I3 are provided respectively with pitch bars 55 and 55 each of the pitch bars 55 and 55 being pivotally mounted through the medium of a pivot bolt 5'! to a bracket plate 58 carried by one of the forward rails 3 of the rearward gangs of discs 253 and 29. The forward ends of the pitch bars 55 and 56 are slidably received in box-like stop sleeves carried by the frames of the respective discing units. In the case of the pitch bar 56, which is provided for the right discing unit I3, a stop sleeve 6E receives the forward end of the pitch bar, this sleeve having the underside of its forward end xed by a pivot 62 to a bracket structure E3 bolted or otherwise secured to the respective forward rail I4. As the discing unit I3 is swung forward by draft applied to the draw bar mechanism, the pitch bar 5t is drawn through the stop sleeve 58 until the forward end of the sleeve 60 is engaged by a stop pin e4 or a stop bolt, or the equivalent, adjustably and selectively received in any one of a plurality of corresponding apertures 64a in the forward end of the pitch bar 5B as best indicated in Fig. 2. The stop pin `64 having engaged the end of the stop sleeve 65,

respective swivel forward swinging movement of the discing unit I3 is checked.

The other pitch bar 55 which is provided for the left discing unit I2, is received in a box-like stop sleeve -65 similar to the stop sleeve 6D, the

forward end of the pitch bar 55 being provided with a stop pin 61B like the stop pin 54 and selectively receivable in adjusting holes 65a in the outer portion of the pitch bar 55.

The stop sleeve 65 is pvotally carried by the left discing unit I2 at a position slightly forward of the respective forward rail I4, this pivotal mounting being, however, bodily shiftabie with reference to the respective forward rail lli. Such a mounting, which is best illustrated in Fig. 8, is made necessary because, under specific discing operations, the pitch bar 55 is locked in position in its stop sleeve 55, it being desired to retain such locked relationship even when right hand turns are made in changing directions across a held. To accomplish these ends, the underside of the stop sleeve 65 is provided with a pivoting pin 10 (see also Fig. 6) which extends through and is pivotally secured near one end of an elongated mounting arm 1I, a nut 10a or the like being employed to retain the parts in operative relation. The other end of the arm 'iI is pivotally mounted as by means of a pivot bolt 'i2 in the outer end of a forwardly projecting bracket i3 carried on the respective forward rail I4 near the outer end of the latter. rhe end of the mounting arm 'II carrying the stop sleeve 55 is normally retained in fixed position with respect to the rail I4 through the medium of a latch 'i4 having a hook-like detent portion 14a adapted to engage about a fixed upstanding latch pin 'I5 conveniently welded :to the adjacent forward face of the rail I4. The latch I4 is mounted upon the respective end of the mounting arm 'Il by any pivot means 'I5 such as a pin or bolt, and it is adapted to be swung about the pivot means le to withdraw the hook-like detent portion Ma from the latch pin l5 through the medium of an actuating chain I1 connected with the latch "i4 through suitable linkage 18. The linkage Iii is pivotally mounted on an auxiliary arm 'i9 which is in turn pivoted near the outer end of the mounting arm II by means of a pivot 3i). The two arms 1I and 15 carry a connecting spring 82 which tends normally to draw them together to maintain the normal latching position illustrated in Fig. 8. When draft iS applied to the chain I'I and the linkage 18, thereby tending to swing the auxiliary arm 'I9 about its pivot til,

A the swinging end of the arm 'I3 is drawn away from the respective end of the mounting arm 'I as the latch 'i4 swings upon its pivot means i5 to disengage the detent 14a from the latch pin "i5, When the parts are to be returned from disengaged position to latching position, as hereinafter described, the spring 82 will cause the latch I4 to be returned to latching position with respect to the latch pin 15.

The locking of the stop sleeve 55 upon the pitch bar 55 for any given set of discing operations, which locked relationship is not to be disturbed in connection with right hand turns, is accomplished through the medium of a dog pin 85 which is carried upon one end of a locking arm 66 whose other end is pivoted at 81 upon ears 8B carried by the rearward end of the stop sleeve 55. The dog pin 85 is adapted to be selectively received in any one of the holes 66a in the forward end of the pitch bar 55, such selection being made in accordance with discing operations to be acacsd'eee complished. A spring 90, which has oneend connected to an adjacent wall portion of thestop sleeve 55, extends through an opening Si in the l locking arm 86, its other end being atta ied to the extremity of an outstanding bracket 2 secured to the locking arm 86. Thus the spring 95 tends to force the dog pin 35 (see also Fig. 5) into engagement with the pitch bar 55 for reception of the pin 85 in any appropriate hole. The dog pin 85, adapted to be withdrawn from engagement with the pitch bar 55 through the medium of a bent lever 94 pivoted at 95 upon ears Sli on an adjacent wall portion of the stop sleeve 55, the inner end of the bent lever 9/5 being provided with a roller 91 which bears upon the inner wall of the locking arm 86. The outer end of the bent lever 94 has a cable 98 attached thereto which leads to the seat of the driver of a tractor or other implement by which the harrow is being pulled. By means of this cable 98, the dog pin may be withdrawn from the pitch bar when necessary, draft upon the cable 93 being all that is required to effect the withdrawal, and the spring 95 returning the dog pin B5 into engagement with the bar upon release of the cable 93.

As will be noted from Fig. 5, one or two addi tional holes 99 are provided in an intermediate portion of the pitch bar 55 so that the dog pin 85 may engage therein to retain the discing units i2 and I3 in the non-discing position illustrated. in Fig. 2 in order that the harrow may be transported.

Operation The assembled disc harrow containing the im provements of this invention is adapted to be disposed either in the operative discing position shown in Fig. 1, or in the non-discing or transe port position shown in Fig. 2.

When the harrow is to be transported to or from a place of use,'the dog pin 85 carried by the locking arm 86, Fig. 5, will be placed in one of the intermediate holes 99 so that, when draft is applied by a tractor or similar draft implement to the link 45 of the draw bar mechanism, the parallel relationship of the squadron discing units i2 and I3 with respect 'to the rearward discing mechanism 21 will be maintained. Thus, the assembled harrow construction may be readily transported, the discs traveling straight ahead upon the supporting surfacevwithout the producn tion of the normal discing functions.

When it is desired to perform the usual discing operations, the operator will pull the cable et of the locking mechanism whereby to actuate the bent lever 94 and withdraw the dog pin 35 from the respective hole 99. The dog pin 85 being thus withdrawn, forward movement of the tractor will cause the two squadron discing units I2 and I3 to swingv about their hinge pins 38 with respect to the rearward discing mechanism 21 until they assume a position such as illustrated in Fig. 1. The stop pins 54 and 66 of the pitch bars 56 and 55 will have been adjusted in the respective holes 64a and 66a in the forward ends of the pitch bars so as to cause the swinging movement of the discing units I2 and I3 to be stopped at the particular angular or offset position best adapted to the discing operations to be performed. Such settings may be inthe extreme forward holes as illustrated in Figs. 1 and 2. D-uring swinging movement of the discing units I2 and I3 to the angular position desired, the tractor operator will have maintained draft ing which the cable 98 is released to allow the dog pin 85 to drop into a corresponding hole 65a and thereby lock the pitch bar 55 in the respective stop sleeve 55. The spacings of the hole 66a with respect to the position of the dog pin S5 and the stop pin 66 when it engages the forward end of the stop sleeve 65, are, of course, such as to permit the dog pin 85 to drop into one of the holes 56a when the stop pin 55 reaches upon the lock-releasing cable 93 until the required relationships have been attained, followthe limit of its movement with respect to the forward end of the stop sleeve 55.

By reason of the locking arrangement just described, and the provision of the automatic latching and unlatching mechanism including the latch 14 for permitting right hand turns, any required offsetting of the squadron disc units for a given discing operation may be maintained throughout the entire discing procedure. When only left hand turns are required, the oset relan tionship illustrated in Fig. 1 is maintained and this, of course, facilitates left hand turns.

When right hand turns are required to be made in connection with discing operations, restoration of the squadron disc units I2 and I5 to the discing position illustrated in Fig. 2 is automatically effected through the medium of the automatically tensioned actuating chain 'i1 connected with the automatic latch 14. The forward end of the chain 11 is attached in a conventional fashion to an appropriate attachment bracket ii (Fig. 1) having a suitable chain receiving slot or opening |02, this bracket IGI being connected in any conventional manner with the tractor as through the medium of a quadrant bar or other bar |84 at the rear of the tractor. rihe bracket im is conventionally carried at the left side of the tractor so that when the tractor swings to the right and pulls the draw bar link .15 to the right, the chain 11 is tensioned, thus pulling forward the auxiliary unlatching arm 19 and the linkage 13 carried thereby so that a draft is placed upon the latch 14 to cause the latter to swing about its pivot mounting 16 to disengage its detent 14a from the upstanding latch pin 15 affixed on the foreward face of the respective front rail I4. In View of the tension thus placed upon the chain 11 under the influence of the turning movement of the tractor toward the right, the effective shortening of the chain 11 in turn produces the effect of converting the draw bar links 45 and 46 into thrust links or compression members so that the discing units i2 and I3 are forced rearward about the hinge pins 38 into positions substantially as illustrated in Fig. 2. In fact the swinging ends of discing units I2 and I3 may be permitted to approach the framework of the rearward discing mechanism 21 more closely than illustrated so that the forward discs IS of the two units I2 and I3 are pitched somewhat to the right from the full line position of Fig. 2thereby further facilitating a right turn. Under these circumstances the mounting arm 1I upon which the stop sleeve 55 is mounted by means of its pivot pin 'I9 moves forward away from the corresponding front rail I4, the stop sleeve 55 and the pitch bar 55 following due to the engagement of the dog pin 85 in the respective hole 56a.

When the right hand turn has been completed, and the tractor straightens out for forward draft again, such forward pull again causes the discing units I2 and I3 to swing about their hinge pins 38 until the predetermined offset discing relationship of Fig. 1 is reestablished. During the final portion of this return movement,

aeadecs the pointed rearward end of the latch 14 (as best seen in Fig. 8) causes the latch to be guided past the latch pin 15 toward the normal operating position illustrated, the final movement of the latch 15 about the pivot means 16 being effected by action of the spring 82 which pulls the auxiliary arm 19 toward the mounting arm 'Il and thereby causes the linkage 18 to swing the detent 14a behind the latch pin 15.

It will be observed that the location of the spreader bar I6 in its-plane above the plane of operation of the squadron discing units i2 and I3 permits freedom of movement of the units IZI and Vi3 without the possibility of interference of the spreader bar IU and without the necessity of any special shaping of the spreader bar which would be required if it were mounted on the forward portions of the units I2 and I3. Thus, the principal length of the spreader bar I lies in a horizontal plane and is perfectly straight. Only short offset portions which are necessary for connection with the swivel mounts 2| need to be disposed out of such horizontal plane. Therefore, this construction makes it possible to employ a relatively lightweight, straight, rigid, compressible spreader member as the sole means for maintaining a proper operative relationship between the squadron discing units I2 and I3. At the same time the draft mechanism or draw bar mechanism provided by the draft links 45 and d6 may be comparatively light in weight and simple in construction. By these means a minimumof dead weight of the draft mechanism is transferred to the tractor. Thus, the traction of the tractor is not interfered with by an undue amount of dead weight, and the penetration of the forward discs I8 of the squadron discing units I2 and I3 is not unduly increased by the dead weight of the spreader bar I0 or other position maintaining means.

It will also be observed that the locking means provided by the dog pin 85 and associated parts and the latch releasing mechanism provided by the automatic latch 14, the actuating chain 11 and associated parts, permits establishment of any required predetermined offset for given discing operations, the automatic latch releasing` means permitting right hand turning without disturbance of the predetermined offset mentioned.

Throughout the operations, the simple form of spreader bar I0 disclosed functions continuously to maintain a proper relationship between the discing units I2 and I3, the functioning of the locking means 85, 86 and of the automatic latch 1d and associated parts being imparted through the bar I0 from the unit I2 to the unit I3.

As the locking means 85, 86 and the stop sleeve 65 shift with the pitch bar 55 when the latch 'Ill is released from the latch pin 15, the front rail I4 of the discing unit I2 serves as a supporting guide in conjunction with the mounting bar 1I. The pitch bars 55 and 56 remain always in substantially parallel relationship, the bar I6 always being substantially parallel to a line through the hinge pins 38 on the rearward discing'mechanism 21.

Since many variations of the generic invention herein disclosed will no doubt become apparent to those skilled in this art, it is intended to cover all such modifications as fall within the scope of the claims.

1 vclaim as my invention:

1. In combination in a disc harrow: a rearward transversely disposed discing mechanism; a

plurality of forward discing units individually pivotally connected to said rearward discing mechanism at points adjacent one end of each of said units whereby said units may ble moved horizontally between positions substantially parallel with said rearward discing mechanism and angularly disposed offset discing positions; a rigid spreader bar interconnecting said discing units at points removed from the points of pivotal connection with said mechanism, said bar being rigid and lying above said discing units and out of the plane of horizontal movement of said units to maintain proper spacing of said units in all positions of adjustment; and plural draft means connected respectively with said units and adapted to be attached to a tractive implement.

2. A combination as in claim 1 wherein said rigid spreader bar overlies at least portions of said discing units and is connected to said units at points rearward of their forward edges.

3. A combination as in claim 2 wherein said draft means are connected to said respective discing units at points forward of said points of connection of said spreader bar to said units, said draft means being flexibly connected together.

d. A combination as in claim 1 including: a pitch bar pivotally connected at one end with said rearward discing mechanism and adjustably connected at its other end with one of said discing units; means to lock said pitch bar in adjusted position upon said one discing unit; releasablc latch means between said pitch bar and said one discing unit for automatically releasing said pitch bar from said one discing unit; and means connected with said releasable latch means and adapted to be attached to the tractive implement for automatic release of said latch upon predetermined movement of said implement with respect to said harrow.

5. A combination as in claim l wherein said rigid spreader bar is an elongated horizontally disposed, substantially straight, compressionresistant tie bar having short offset depending ends connecting the spreader bar to the respective discing units through vertical and horizontal pivot means 6. A combination asin claim 1 including: a pitch bar for controlling the swinging movement of one of said discng units; one end of said pitch bar being pivotally ,connected to said rearward discing mechanism and the other end of said pitch bar being adjustably connected with one of said discing units; and locking means connected with said one discing unit to retain said pitch bar in a predetermined adjusted position with respect to said one discing unit.

7. In combination in a disc harrow: a rearward transverse frame structure carrying a gang of discs adapted to be operatively disposed in position transversely to a direction of travel; a plurality of forward frames respectively carrying gangs of discs, said forward frames beingI individually pivotally connected to said rearward frame structure at points adjacent one end of each of said forward frames; an elongated rigid spacer bar lying at a level above said forward frames in a position substantially parallel to said rearward frame structure, said spacer bar having `short depending end portions pivotally fixed to `said forward frames 'to maintain a predetermined spaced relationship between said forward frames, the lentgh of said spacer bar approximating the distance between the points of pivotal connection of said forward frames to said rearward frame structure, and the points of connection of said spacer bar with said forward frames being remote from said points of pivotal connection of said forward frames to said rearward frame structure; and draft means carried by portions of each of said forward frames for connection with a tractive implement.

8. A combination as in claim 7 wherein said draft means comprises a pair of converging, nexibly connected, non-bracing draft links flexibly connected with the respective forward disc frames. n

9. A combination as in claim 7 including: a plurality of pitch bars respectively pivotally connected at one end with said rearward frame structure and at the other end slidably connected with the respective forward frames; means between said pitch bars and their respective forward frames for adjustably limiting such slidable connection in accordanceV with desired movement of said forward frames about their pivotal connections with said rearward frame structure; and locking means for securing at least one of said pitch bars in a predetermined position of adjustment with respect to the respective forward frames.

10. A combination as in claim 7 including: a plurality of pitch bars respectively pivotally connected at one end with Vsaid rearward frame structure and at the other end slidably connected .f

with the respective forward frames; means between said pitch bars and their respective forward frames for adjustably limiting such slidable connection in accordance with desired movement of said forward frames about their pivotal connections with said rearward frame structure; locking means for securing at least one of said pitch bars in a predetermined position of adjustment with respect to the respective forward frames; and automatic latchmeans adapted to release the last mentioned pitch bar when locked upon the respective forward frame and comprising actuating meansadapted to be connected to the tractive implement forautomatic release of said latch means upon predetermined movement of said tractive implement with respect to said disc harrow.

11. Avcombination as in claim 7 wherein said spacer bar is attached to said forward frames and is arranged thereover to impose the weight of said spacer bar upon said frames and the respective discs at points rearward of forward members of said forward frames.

12. A combination according to claim 1 wherein said spreader bar is attached to said discing units at positions rearward of the forward portions thereof to impose the weight of said spreader bar upon said discing units at positions rearward of the forward "portions thereof, said spreader bar being relatively light in weight, and said draft means comprising converging draft links relatively light in weight, whereby to impose a minimum of added dead weight upon said forward discing units.

13.7Incombination in a disc harrow: a rearward transversely disposed discing mechanism; Va plurality of forward discing units individually pivotally connected to said rearward discing mechanism at points adjacenty one end of each of said units whereby said units may be moved vhorizontally between positions substantially parallel with said rearward discing mechanism and angularly" disposed oiset discing positions; a rigid spreader bar overlying said forward discing uniti n substantial parallelism with `said rear ward discing -mechanism and interconnecting' said discing units at points removed fromthe points of pivotal connection with said mechanism, the ends of said spreader bar being connected by vertical and horizontal .pivot means with the respective forward discing units; pitch means connecting said rearward discing mechanism and one of said forward discing units; adjustable means on such one forward unit and receiving said pitch means; and means to lock said adjustable means in adjusted position on said pitch means to maintain a predetermined offset relationship.

14. In combination in a disc harrow: a rearward transversely disposed discing mechanism; a plurality of forward discing units individually pivotally connected to said rearward discing mechanism at points adjacent one end of each of said units whereby said units may be moved horizontally between positions substantially parallel with said 'rearward discing mechanism and angularly disposed offset discing positions; a rigid spreader bar interconnecting said discing units at points removed from the points of pivotal lconnection with said rearward discing mechanism, said b ar having its ends mounted upon said forward discing units by vertical and horizontal pivots; pitch means connecting said rearward discing mechanism and one of said forward discing units; adjustable means on such one forward unit and receiving said pitch means; means between said adjustable means and said pitch means to lock said adjustable means in adjusted position Yon said pitch means to maintain a predetermined offset relationship; latch-controlled means connected with said one forward unit and on which said adjustable means vis mounted; and releasable latch means on said latch-controlled means and said one forward unit, said latch means providing for movement of said pitch means and adjustable means together with -respect to said one forward unit upon release of said latch means.

15. A combination as in lclaim 14 including means attachable to a tractor and connected with said latch-means for automatically releasing said latch means upon vturning the tractor in one-direction.-

16. In combination in a'disc harrcw: a rearward transverse frame structure carrying a gang of discs-adapted to be operatively disposed in position transverse to a direction of travel; a plurality lof forwardV frames respectively carrying gangs of discs, said forward frames being individually pivotally connected to said rearward frame structure at point-s adjacent one end of each of said forward frames; an elongated `rigid spacer bar xed to said forward frames to maintainupredetermined spaced relationshipsof said forward frames, said spacer bar being xed at its ends to said forward frames by horizontal and vertical pivot means, said spacer bar overlyingvsaid forward frames in substantial parallelism with said discing mechanism; a pitch bar pivotally connected with said rearward frame structure and movably connected with one of said forward frames; means on said one forward frame receiving said pitch bar to effect such movable connection; and means for locking said leceiving means in adjusted position on said'pitch 17. A combination as in claim 16 including latch means Carrying :said receiving means, said latch means being normally latched to .Said one fOIWard Vfrmfl@ to #cooperate -withsaid locking means to retain said pitch bar in adjusted position with respect to said one forward frame, said latch means being releasable for relative movement of said locking means.

18. In combination in a disc harrow: a rearward transversely disposed discing mechanism; a plurality of forward discing units individually pivotally connected to said rearward discing mechanism at points adjacent one end of each of said units whereby said units may be moved horizontally between positions substantially parallel with said rearward discing mechanism and angularly disposed offset discing position; a rigid spreader bar interconnecting said discing units at points removed from the points of pivotal connection with said mechanism, said spreader bar overlying said forward discing units in substantial parallelism with said rearward discing mechanism; means connecting the ends of said spreader bar with said disoing units and comprising short depending arms between said bar and units and means providing horizontal and vertical pivot connections between the ends of said bar and said discing units; and means at the forward side of each discing unit for flexibly connecting respective draft means.

19. A combination as in claim 18 including: means disposed between said discing mechanism and the respective units to control said angular offset discing positions.

30 20. A combination as in claim 18 including:

means disposed between said discing mechanism and the respective units to control said angular offset discing positions; and means to lock said control means in a given position to maintain a given offset.

21. A combination yas in claim 18 including: means disposed between said discing mechanism and the respective units to control said angular offset discing positions; means to lock said control means in a given position to maintain a given offset; and latch means connected with said respective units for normally holding said lock means, and releasable to permit bodily shift of said lock means.

LOYD E. HECKATHORN.

REFERENCES `CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 408,338 Davis Aug. 6, 1889 1,322,066 Sharp Nov. 18, 1919 1,627,356 Towner May 3,. 192'? 1,630,996 Wright May 31, 1927 2,221,461 Sjogren et al Nov. 12, 1940 2,230,041 Lindgren et al. Jan. 28,l 1941 2,251,788 Goble Aug. 5, 1941 2,349,852 Dyrr May 30, 1944 

